Vision system camera with mount for multiple lens types

ABSTRACT

This invention provides a vision system housing having a front plate assembly that accommodates a plurality of lens mount types. The front plate includes a central aperture that is located at a predetermined axial (camera axis) distance from a plane of an image sensor. The aperture is stepped from a wider diameter adjacent to the front to a narrower diameter more adjacent to the sensor. This arrangement enables threaded mounting of a plurality of lens mount types, for example M12 and C-Mount. The exterior (front) surface of the front plate includes threaded holes and a removable spring clip arrangement constructed to accommodate a liquid lens positioned over the aperture with an associated lens assembly mounted within the aperture and in optical communication with the liquid lens. The lens is operated using an electrical connection provided by a cable that interconnects with a multi-pin socket positioned on the front plate.

FIELD OF THE INVENTION

This invention relates to vision system cameras and more particularly tolens mounts for vision system cameras.

BACKGROUND OF THE INVENTION

Vision systems that perform measurement, inspection, alignment ofobjects and/or decoding of symbology (e.g. bar codes) are used in a widerange of applications and industries. These systems are based around theuse of an image sensor, which acquires images (typically grayscale orcolor, and in one, two or three dimensions) of the subject or object,and processes these acquired images using an on-board or interconnectedvision system processor. The processor generally includes bothprocessing hardware and non-transitory computer-readable programinstructions that perform one or more vision system processes togenerate a desired output based upon the image's processed information.This image information is typically provided within an array of imagepixels each having various colors and/or intensities. In the example ofa symbology (barcode) reader, the user or automated process acquires animage of an object that is believed to contain one or more barcodes. Theimage is processed to identify barcode features, which are then decodedby a decoding process and/or processor obtain the inherent alphanumericdata represented by the code.

It is increasingly desirable to provide vision systems and associatedvision system components that can be used for a variety of purposes. Byway of example, an integrated sensor and single instruction, multipledata (SIMD) processor, which can be termed a vision system on a chip(VSoC), is shown and described in U.S. patent application Ser. No.12/184,187, entitled VISION SENSORS, SYSTEMS AND METHODS, by E. JohnMcGarry, et al., the teachings of which are incorporated by reference asuseful background information. This architecture provided a highlyversatile and widely applicable vision system platform for a variety ofvision system tasks. The ability to provide a versatile system reducescosts by eliminating the need to provide a number of purpose-builtvision system arrangements for specific applications. It is thereforedesirable to provide such versatile vision system platforms. Othercurrently available arrangements of sensors and processors (e.g. digitalsignal processors (DSPs) can also be employed to provide a relativelycompact and robust vision system.

While programs can be readily adapted for a particular vision systemtask, it is more of a challenge to adapt the system's physical packageto that task. For example, some vision tasks call for a larger lens,such as a cine or C-mount unit, while others can be accomplished bestwith a smaller M12 thread (12 mm×0.5 mm thread) lens, also termed an“S-mount”, or more basically, an “M12” lens. Others are best suited to aliquid lens, or a similar arrangement. By way of further background, aliquid lens uses two iso-density liquids—oil is an insulator while wateris a conductor. The variation of voltage passed through the lens bysurrounding circuitry leads to a change of curvature of theliquid-liquid interface, which in turn leads to a change of the focallength of the lens. Some significant advantages in the use of a liquidlens are the lens' ruggedness (it is free of mechanical moving parts),its fast response times, its relatively good optical quality, and itslow power consumption and size. The use of a liquid lens can desirablysimplify installation, setup and maintenance of the vision system byeliminating the need to manually touch the lens. Relative to otherautofocus mechanisms, the liquid lens has extremely fast response times.It is also ideal for applications with reading distances that changefrom object-to-object (surface-to-surface) or during the changeover fromthe reading of one object to another object.

The choice of lens type (e.g. C-mount, M12, liquid lens, etc.) can bedriven by such factors as lighting/illumination, field of view, focaldistance, relative angle of the camera axis and imaged surface, and thefineness of details on the imaged surface. In addition, the cost of thelens and/or the available space for mounting the vision system can drivethe choice of lens.

It is therefore desirable to provide a vision system that can readilyaccommodate a variety of lens types while avoiding the need of costlychanges to the vision system's physical housing or package. This visionsystem should be able to employ multiple lens types with no reduction inquality of the acquired image when compared with using a system thatprovides a discrete, purpose-built lens mount.

SUMMARY OF THE INVENTION

This invention overcomes the disadvantages of the prior art by providinga vision system housing having a front plate assembly that accommodatesa plurality of lens mount types. The front plate includes a centralaperture that is located at a predetermined axial (camera axis) distancefrom a plane of an image sensor. The aperture is stepped from a widerdiameter adjacent to the front to a narrower diameter more adjacent tothe sensor. This arrangement of diameter and relative depth within thefront plate enables threaded mounting of a plurality of lens mounttypes, illustratively an M12 lens mount and C-Mount. The threaded basefor the M12 lens mount is provided in the smaller-diameter interiorportion of the front plate aperture, adjacent to the sensor.Additionally, the threaded base for the C-Mount lens is provided at thefront of the front plate, adjacent to the exterior surface of the frontplate and housing. The exterior (front) surface of the front plateincludes threaded holes and a spring clip arrangement (fastened byscrews) constructed and arranged to accommodate a liquid lens positionedover the aperture with an associated lens assembly mounted within theaperture and in optical communication with the liquid lens. The lens isoperated using an electrical connection provided by a cable thatinterconnects with a multi-pin socket positioned on the front plateaside the aperture. The socket interconnects with processor circuitrywithin the housing that enables control of the liquid lens.

In an illustrative embodiment the vision system defines a housing thatincludes a front plate assembly comprising an aperture aligned relativeto an image sensor located within an interior of the housing, theaperture including an outer step having a first diameter and in innerstep have a second diameter smaller than the first diameter. The firststep is constructed and arranged to receive a first lens type base andthe second step is constructed and arranged to receive a second lenstype base. By way of example, the outer step is constructed and arrangedto receive a C-mount lens base and the inner step is constructed andarranged to receive an M12 lens base. Moreover, the front plate assemblyis constructed and arranged to receive, over the aperture, a liquid lensmodule. A clip assembly, illustratively comprising a spring assemblywith retaining shoulders that is secured by screws to threaded holesaround the aperture, engages portions of the housing or shell of theliquid lens module. The front plate assembly also illustrativelyincludes a first socket, interconnected with control circuitry withinthe housing, which receives a cable to operate the liquid lens module. Asecond socket can also interconnect the control circuitry with anilluminator. The front plate assembly is illustratively attached to abody section of the housing bolts having ends that are exposed at theouter face of the front plate assembly and pass into the body section.These ends can include threaded holes that receive fasteners that allowattachment of the front plate assembly to a mount or accessory.

More generally, in an illustrative embodiment, the vision system housingincludes a main body section having an image sensor within the interiorthereof. A front plate assembly is attached to the main body section.The front plate assembly includes threaded structures for selectively,removably and directly attaching at least three discrete types of lensthereto. By way of example, the three lens types can include a C-mountlens, and M12 lens and a liquid lens module.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention description below refers to the accompanying drawings, ofwhich:

FIG. 1 is a perspective view of a vision system including a housing thatallows for the removable attachment of a plurality of different lensmount types, showing the housing free of an attached lens, according toan illustrative embodiment;

FIG. 2 is a side cross section of the housing taken along Line 2-2 ofFIG. 1;

FIG. 3 is a perspective view of the vision system of FIG. 1 in which thehousing includes an exemplary M12 type lens attached thereto, accordingto an illustrative embodiment;

FIG. 4 is a side cross section of the housing taken along Line 4-4 ofFIG. 3;

FIG. 5 is a perspective view of the vision system of FIG. 1 in which thehousing includes an exemplary C-Mount type lens attached thereto,according to an illustrative embodiment;

FIG. 6 is a side cross section of the housing taken along Line 6-6 ofFIG. 5;

FIG. 7 is a perspective view of the vision system shown in FIG. 6 inwhich the housing includes the exemplary C-Mount type lens attachedthereto, in which the lens is covered by an optional shroud assembly,according to an illustrative embodiment;

FIG. 8 is a perspective view of the vision system of FIG. 1 in which thehousing includes an exemplary liquid type lens attached thereto,according to an illustrative embodiment;

FIG. 9 is a side cross section of the housing taken along Line 9-9 ofFIG. 8; and

FIG. 10 is a front view of the vision system shown in FIG. 8 in whichthe housing includes the exemplary liquid type lens attached thereto,according to an illustrative embodiment.

DETAILED DESCRIPTION

With reference to FIGS. 1 and 2, a vision system that includes anexternal package or “housing” 100 is shown in detail. The housing 100can be constructed from polymer, metal, composite or a variety ofmaterials in accordance with ordinary skill. In an embodiment, itconsists of a front plate section 110, a main body section 112 and arear section 114. The front plate section (or “front plate”) 110 isjoined to the main body and rear sections using four threaded bolts 116that are seated within wells in the front plate 110, and that engagethreaded holes in the rear section, thereby compressing the threesections together against gaskets 118 that seal the housing againstinfiltration of moisture and other environmental agents. Theconstruction of the housing is highly variable in alternate embodiments.For example, the housing can be constructed with an integrated orunitary rear and main body or a unitary front plate and main body.Likewise, other fastening techniques can be employed, such as employingjoining clamps or clips between sections.

In this embodiment, the bolts 116 are located adjacent to each of fourcorners of the somewhat rectangular-cross-section housing. The bolts 116each contain respective threaded wells at their front end that allow forthe attachment of accessories using threaded fasteners, or theattachment of the housing itself to a mounting surface. Alternatively,the bolts 116 can be substituted with appropriate bolts that also passthrough holes in a mounting surface or accessory (not shown), andcollectively join the surface/accessory to the sections of the housingin appropriate compression.

The interior of the housing 100 supports an image sensor 212 (FIG. 2)that is arranged to acquire each image frame as an array of individualimage pixels. In an embodiment, the sensor array is a CMOS sensor 212(also termed an “imager”), which acquires image data in the form ofpixel data. A cover glass 210 id provided to protect the sensor array212. The sensor 212 is mounted on a printed circuit board 250 secured asdepicted near the front end of the housing. The sensor circuit board 250also illustratively includes processing circuitry (e.g. a digital signalprocessor DSP) that receives the pixel data from the sensor array 212and performs various vision system processes on the data in accordancewith non-transitory computer-readable program instructions and/orfirmware instructions. The sensor circuit board 250 is interconnectedwith various power, control and other associated circuit componentslocated on a circuit board 220 in the rear 114 of the housing. The twoboard assemblies 220, 250 are illustratively interconnected by amulti-lead cable 222 in this embodiment. Other arrangements of circuitryand interconnections are expressly contemplated. For example, in anotherembodiment, a VSoC arrangement (described above) can be provided toperform image acquisition and processing. The rear section 114 (and/orother sections 110, 112 of the housing) can be constructed from aluminumso as to act as a heat sink that assists in dissipating heat generatedwithin the housing by the circuitry (described further below).

An external connector (or a plurality of connectors) 130 are located atthe rear side of the housing 100 for providing power, data and/or otherinterface functions. The connector(s) is/are operatively connected tothe circuit board 220. The rear also includes an external status andcontrol panel 140 that provides the user with status indicators andfeedback on vision system operations (for example, indicating whether asymbol has been properly identified and decoded). Appropriate on/offswitches and other interface buttons can also be provided at thislocation, or at another appropriate location on the housing 100.

The plane of the sensor 212 is oriented perpendicularly to thelongitudinal axis (i.e. camera axis) 230 of the housing 100. It resideswithin a space 240 that is open to an aperture 150 within a centralregion of the front plate 110. The space 240 is bounded by an enclosingwall 242 (having a relatively planar sides that can define a rectangularcross-section tube) that provides clearance for the sensor 212. The wall242 extends from a step face 244 to the surface of the sensor circuitboard 250. The distance DS from the step face 244 to the plane of thesensor 212 is approximately 6 millimeters. The aperture 150 is definedby an outer step 152 and a narrower inner step 154. Each step isthreaded as described below. In particular, the outer step 152 defines adiameter DOS of approximately 25.4 millimeters (1 inch), and a depth(along the axial direction) LOS of approximately 5 millimeters.Likewise, the inner step 154 defines a diameter DIS of approximately 12mm. The outer step 152 is female-threaded to a pitch of 32 threads perinch (TPI) and the inner step 154 is female-threaded to a pitch of 0.5mm. In general, the positioning of the steps and size of the space areconstructed and arranged to accommodate the focal length of each lenstype being employed herein.

In an embodiment, the front plate assembly 110 is constructed from metal(e.g. die cast aluminum alloy), which is finished using an appropriatemachining process. The casting includes the depicted recesses 152, 154and other supporting structures (i.e. walls 242, 251 and 252) for lensesand other internal components. Notably, the supporting walls 242 (etc.),which contact and/or surround the sensor circuit board 250 assist indirecting heat away from the board 250 and its associated circuitcomponents and into the housing structure, where the heat is dissipatedinto the surrounding ambient air. In alternate embodiments the layoutand configuration of the supporting structures can vary. In general, thethickness of walls used in such supporting structures is selected toprovide sufficient structural strength with respect to the materialemployed in constructing the front plate 110. The front plate assembly110 includes, along its front face 164, a plurality of threaded holes160 that can be female-threaded to any appropriate size, so as acceptcorresponding threaded screws (described below). These screws can beused to attach a plurality of fittings and accessories to the frontplate.

Note that directional terms such as “front”, “rear”, “up”, “down”, “top”bottom”, “right”, and “left”, as well as their variants and synonyms,should be taken as relative conventions only, and not as absoluteindications of orientation of a structure relative to the direction ofprevailing gravitational force.

With reference particularly to FIG. 1, the face 164 of the front plateassembly 110 includes a pair of connection sockets 170 and 172respectively oriented to the right and left of the aperture 150 (asviewed from the front). Both sockets include respective connectors,which are interconnected with the system's processor circuitry (i.e. 250and 220). The right socket 170 is employed to operate the optics of aliquid lens (described above, and again below). The left socket 172 isemployed to interconnect and operate an illumination assembly that canbe directly attached to the front plate via threaded holes 160 or can beseparately mounted. The illumination assembly is described in furtherdetail in commonly assigned U.S. patent application Ser. No. 13/302,858,entitled CAMERA SYSTEM WITH EXCHANGABLE ILLUMINATION ASSEMBLY, byLaurens Nunnink, filed on Nov. 22, 2011, and the teachings of which areexpressly incorporated herein by reference as useful backgroundinformation.

The perimeter 180 of the aperture 150 includes a circumferential springassembly 182 with a pair of diametrically opposed, radially inwardlydirected retaining shoulders 184. The spring assembly 182 is removablysecured to the front face 164 by opposed screws 186 (M2 thread in thisembodiment) that threadingly seat into holes (502 in FIG. 5). In anembodiment, the screws 186 are separated by a distance (on-center) ofapproximately 28 millimeters, taken through the camera axis (230). Asdescribed further below, the removable spring assembly is constructedand arranged to retain a liquid lens assembly.

It is contemplated that a user receives a housing 100 with a cap (notshown) to protect the aperture and sensor, and that the applicable lensis purchased separately—to be attached by the user in a straightforwardmanner as described further below. Alternatively, the lens can beprovided to the housing by the manufacturer. In either case, there are awide range of lens choices available.

Having described the generalized construction and function of thehousing 100 and front plate assembly 110 according to an illustrativeembodiment, the implementation of various types of lenses in conjunctionwith the housing is now described in further detail. With reference toFIGS. 3 and 4, the housing 110 is provided with an attached M12 lens 310according to an embodiment. By way of non-limiting example, the lens isa commercially available M12 lens with a conventional M12 threaded base.The male thread of the lens is secured into the female thread of thenarrower, more-inset step 154, and is stopped from further inwardthreading, and generally locked in place using a counter nut 320, whichis initially threaded onto the lens 310 base before attachment to thefront plate assembly 110. The applied counter nut 320 can be adhered bythe manufacturer (or another party) in place at an appropriate locationalong the lens using adhesive or another fixing technique. This ensuresthat, when the lens is tightened into place (e.g. by the user) to form atight engagement with the front face 430 of the step 154 as shown, it isalso positioned at a proper, predetermined distance with respect to thesensor's image plane. The lens 310 is thereby locked in place at adesired offset (to provide proper focal length) with respect to theplane of the sensor 212. Alternatively, where the user seeks to vary themounting position of the lens, the counter nut can remain unfixed to thelens thread and counter-rotated by the user (or another party) to securethe lens in a desired position.

The front end of the lens can include a radially outwardly oriented ring330 that engages the inner perimeter of an optional, frustoconicallyshaped stopper 410 (FIG. 4). The stopper protects the region of theaperture 150 between the lens front and the outer step 152, and avoidsinadvertent loosening or readjustment of the tightened lens/counter ring310/320 and protects against infiltration of dirt and moisture. Thestopper 410 can be any acceptable shape, or alternatively omitted. It issecured to the front plate assembly 110 by a pressed-in friction fitthat resides against the female threads in the outer step 152. It isillustratively mounted by pressing it into the thread well until itseats against the front face 430 of the inner step 154 as shown (FIG.4). The stopper can be constructed from an elastomeric material. Inalternate embodiments, the stopper can employ a different securingsystem with respect to the housing front plate assembly 110, such asclips or mating threads.

It should be clear that attachment and detachment of the exemplary M12lens 310 is relatively straightforward, and entails the threadedrotation of only a few components with respect to the inner step 154 and(optionally) the outer step 152. Thus, the user or the manufacturer candesirably assemble an M12 lens vision system from a few readilyavailable components. Likewise, if the user desires a C-mount-lens-basedvision system, the housing can be assembled as shown in FIGS. 5-7.

As shown, the male-threaded base 512 of the exemplary C-mount lens 510is threadingly attached to the female threads of the outer step 152 asshown (FIG. 6). The base 512 is tightened until its rear shoulder 620engages the perimeter 180 of the aperture 150. The perimeter 180 isspaced from the plane of the sensor at an appropriate distance so as toprovide the proper focal length for the lens 510 with respect to thesensor's image plane. The perimeter 180 upon which the lens shoulder 620can be slightly recessed (as shown) relative to the surrounding frontface 164 to provide the correct clearance, or it can be raised relativethereto to provide the proper focal length. In alternate embodiments,the step 152 and its front perimeter face can be a lockable insert thatis adjustable within the surrounding front plate assembly (using anouter coaxial thread that mates between the insert and the front plate,for example) to allow the seating location of the lens to vary, therebyvarying the focal length. Notably, the optics of the lens 510, combinedwith the geometry of the front plate assembly 110 focuses received lightrays so that they pass free of interference from the rear end 630 of thelens 510 through the smaller diameter step 154, and into the space 240.In this manner, the light rays received by the lens 510 are focused tocover the area of the sensor 212.

The C-Mount lens can be optionally covered by a shroud (or cover)assembly 710 (FIG. 7) that primarily protects it from ingress ofdirt/contaminants and moisture. The shroud 710 can also serve to protectagainst inadvertent change to the lens settings. The shroud assemblyconsists of a gasket plate 720 that covers the front face (164) and anoverlying shroud base 730. The gasket plate 720 and shroud base includethrough-holes that expose the central threaded holes (120) of each ofthe assembly bolts 116. This allows the system to be mounted asdescribed above or receive additional accessories on top of the shroudbase 730. The gasket plate 720 and shroud base 730 thereby cover andseal the sockets (170, 172) in this configuration. In alternateembodiments, one or both of the sockets 170, 172 can be exposed throughthe gasket plate 720 and shroud base 730. The shroud base 730 and gasketplate 720 are secured to the front plate assembly 110 are compressiblysecured by four screws (not shown) that thread into the screw holes 160formed on the front plate assembly 110. In this embodiment, the shroudbase 730 is countersunk in the region of each threaded hole 160 toreceive a correspondingly shaped machine screw. Different screws or anyother fastener arrangement that secures the shroud base 730 and(optionally) the gasket plate 720 can be employed in alternateembodiments can be employed in alternate embodiments. The front ring 732of the shroud base 730 receives the shroud body 740, which overlies andcovers the lens 510. The shroud body 740 can be constructed as a singlepiece, or from a plurality of pieces (e.g. a main body and nose asshown). It can be secured to the ring 732 by a threaded interconnectionor another fastening arrangement.

Notably, with reference to FIGS. 8-10, the versatility of the housing100 and front plate assembly 110 enables mounting of an electronicallyoperated, auto-focusing liquid lens 810 according to an illustrativeembodiment. As described also above, a liquid lens uses two iso-densityliquids—oil is an insulator while water is a conductor. The variation ofvoltage passed through the lens by surrounding circuitry leads to achange of curvature of the liquid-liquid interface, which in turn leadsto a change of the focal length of the lens. Some significant advantagesin the use of a liquid lens are the lens' ruggedness (it is free ofmechanical moving parts), its fast response times, its relatively goodoptical quality, and its low power consumption and size. The use of aliquid lens can desirably simplify installation, setup and maintenanceof the vision system by eliminating the need to manually touch the lens.As noted above, relative to other autofocus mechanisms, the liquid lenshas extremely fast response times. It is also ideal for applicationswith reading distances that change from object-to-object(surface-to-surface) or during the changeover from the reading of oneobject to another object.

In this embodiment, the exemplary liquid lens 810 can be based upon acommercially available liquid lens component 910 (FIG. 9) available fromVarioptic SA of France. The liquid lens component 910 is mounted withinan outer shell/housing 820 that is secured in place by the springshoulders 184 described above. It is expressly contemplated thatalternate hold-down arrangements for the liquid lens can be employed.For example, the housing can include a C-mount base that engages thethreads of the outer step 152. An advantage of the spring-retained lensarrangement is that it allows for the positioning of the connector cable830 in a location that leads properly to the socket 170 (where thecable's connector 832 is shown connected in FIG. 8). Note that thesocket and connector can be any acceptable multi-pin arrangement thatprovides sufficient connections to control the lens.

The inner face of the lens' outer shell or housing 820 engages an O-ring(or other resilient structure that allows an open central aperture) 920that, in turn, pressurably bears upon the circuit board 922. Thiscircuit board 922 includes the control circuitry employed according tothe art to operate the focal length adjustment of the lens component910. The lens is compressed between the circuit board and the internal,fixed lens assembly 940 that focuses light rays from the liquid lenscomponent onto the sensor 212. The fixed lens assembly 940 is securedinto the front plate assembly 110 by threads that engage the inner step154. A counter ring 942 prevents loosening of this lens assembly 940.The pressure applied by the spring retaining shoulders 184 is sufficientto retain the lens component 910 free of movement and vibration, butthis pressure also remains within the desired specification to avoidover-compression of the lens component 910, which could degradeperformance or burst the lens.

With reference briefly to the front view of FIG. 10, the springretaining shoulders are arranged to engage associated abutments 1010 oneach of opposing sides of the lens outer housing/shell 820. Like thespring assembly hold-down screws 186, the abutments 1010 are located ata non-vertical and non-horizontal angle with respect to the geometry(top, bottom, right and left sides) of the system housing 100. Thisallows for the cable 830 to exit the top end of the lens housing/shell820 free of interference by the hold-down components. In thisembodiment, the spring shoulders 184 (and abutments 1010) are alignedalong a line that is approximately perpendicular to the line between thescrews 186. In alternate embodiments a larger or smaller number ofscrews and/or spring shoulders 184 (among other fastening arrangements)can be used to retain the lens 810 with respect to the front face 164 ofthe housing 100. Likewise, it is contemplated that the overall springassembly can be constructed as a single unit with an appropriate numberof retaining shoulders to secure the lens, or a multi-part unit eachhaving one or more shoulders (as shown).

It is expressly contemplated that the arrangement of components in both(or either of) the internal fixed lens assembly 942 and the overlyingliquid lens module (810) are highly variable in alternate embodiments.The depicted illustrative embodiment is an effective arrangement thatcan be assembled in a straightforward manner by the manufacturer oruser.

It should be clear that the vision system housing and associated frontplate construction provides a highly versatile system for selecting and“directly attaching” a variety of desirable lenses and lens mount typesthat are traditionally not interchangeable on a single housing without(free of) additional adapters. Such adapters can reduce accuracy,increase the chance of loosening of components and generally increasethe system's complexity. The resulting vision system allows for fewerspecialized components and more customization either by the manufactureror end user. More particularly, the system provides the end user withthe ability to change out lens types so that the system can be updatesor re-tasked to a new use from an earlier use, as desired.

The foregoing has been a detailed description of illustrativeembodiments of the invention. Various modifications and additions can bemade without departing from the spirit and scope of this invention. Eachof the various embodiments described above may be combined with otherdescribed embodiments in order to provide multiple features.Furthermore, while the foregoing describes a number of separateembodiments of the apparatus and method of the present invention, whathas been described herein is merely illustrative of the application ofthe principles of the present invention. For example, while theillustrative housing is adapted for use with M12 and C-mount lens bases,it is expressly contemplated that adapters can be employed to allow forattachment of other lens types, such as the T-mount lens—for example theabove-described alternate embodiment having an outer step insert.Likewise, the front plate assembly can be constructed and arranged toprovide a different combination of mounts by appropriately sizing andthreading the stepped apertures. Moreover, while various components areattached using threaded screws, it is expressly contemplated that otherfastener types can be used for various interconnections, such assnap-connectors, rivets, clips, and the like. Also, in an embodiment, aplurality of front plate assemblies can be produced and provided to astandard main body section and rear to allow for further versatility ofthe vision system. In addition, any process or processor herein cancomprise one or more electronic hardware components, software in theform a non-transitory computer-readable medium of program instructions,or a combination of hardware and software. More generally, the term“process” should be taken broadly to include various combinations ofhardware components and/or software program steps that perform one ormore functions in a system or method. Accordingly, this description ismeant to be taken only by way of example, and not to otherwise limit thescope of this invention.

What is claimed is:
 1. A vision system housing comprising: a front plateassembly comprising an aperture aligned relative to an image sensorlocated within an interior of the housing, the aperture including anouter step having a first diameter and in inner step have a seconddiameter smaller than the first diameter; and the outer step beingconstructed and arranged to receive a C-mount lens base and the innerstep being constructed and arranged to receive a M12 lens base.
 2. Thevision system as set forth in claim 1 wherein the outer step and theinner step each include female threads that, respectively engage malethreads in the first lens type base and the second lens type base. 3.The vision system as set forth in claim 1 further comprising a mountingassembly on an outer face of the front plate assembly, adjacent to theaperture constructed and arranged to secure a liquid lens module.
 4. Thevision system as set forth in claim 3 wherein the inner step isconstructed and arranged to engage a fixed lens assembly thatinteroperates with the liquid lens module.
 5. The vision system as setforth in claim 3 further comprising a clip assembly, attached to theouter face of the front plate assembly, that removably engages an outershell of the liquid lens module.
 6. The vision system as set forth inclaim 5 wherein the clip assembly includes spring assembly havingshoulders that pressurably engage portions of the outer shell.
 7. Thevision system as set forth in claim 6 wherein the spring assembly isremovably attached to the outer face of the front plate assembly bythreaded fasteners.
 8. The vision system as set forth in claim 3 whereinthe front plate assembly includes a first socket, interconnected withcontrol circuitry within the housing, that receives a cable to operatethe liquid lens module.
 9. The vision system as set forth in claim 8wherein the front plate assembly includes a second socket,interconnected with control circuitry within the housing, that receivesa cable to operate an illuminator.
 10. The vision system as set forth inclaim 1 wherein the front plate assembly is attached to a body sectionof the housing bolts having ends that are exposed at the outer face ofthe front plate assembly and pass into the body section.
 11. The visionsystem as set forth in claim 10 wherein the bolts include threaded holesfor attaching at least one of a mount and an accessory to the frontplate assembly.
 12. The vision system as set forth in claim 1 whereinthe outer step is constructed and arranged to threadingly receive aC-mount lens base and the front plate assembly includes a plurality ofthreaded holes that receive fasteners for securing a shroud assemblythat covers the C-mount lens.
 13. A vision system housing comprising: amain body section having an image sensor within the interior thereof;and a front plate assembly attached to the main body section, whereinthe front plate assembly includes threaded structures for selectively,removably and directly attaching at least three discrete types of lensthereto; and the front plate assembly includes an aperture having anouter step constructed and arranged to secure a C-mount base and aninner step constructed and arranged to secure an M12 base.
 14. Thevision system as set forth in claim 13 wherein the at least threediscrete lens types include at least an M12 base lens, a C-mount baselens and a liquid lens module.
 15. The vision system as set forth inclaim 13 wherein the front plate assembly includes threaded holes thatreceive fasteners for removably securing the liquid lens module to thefront plate assembly with respect to the aperture.
 16. The vision systemas set forth in claim 15 wherein the fasteners removably secure a springclip assembly that engages a portion of the liquid lens module.